help with larvae lighting

[EMBRYOGUY]

sorry to ask this again, but im struggling to get the right lighting for the larvae. they are constantly attached to the walls, unless i add a good amt of green water.

im not sure if its bec of my lighting is too strong or what. i know others do not use green water at all. with less light im concerned they can not see the rotifers, but at same time i think they are not eating when there heads are facing the wall.

right now i have a 7wt pc over the tank. ive tried a 25 wt clamp light over about 2 feet. it just seems too dark.

i tried 48 hrs of light for the first couple days, but that did not seem to deter my sign. loss in the first 2 days. so i keep them at a day/dark cycles from the start with the next batch.

can people post your larvae tank size and lighting used. also distance away from water surface.

THANK YOU in advance.

 

[mwp]

I'm using a standard 20" Striplight with the 15 watt bulb it came with with a glass top. I was adding 1L of fresh phytoplankton per day, and the tank was running at about 50% of capacity (volume wise)....probably puts the light 6-7 inches above the water's surface. I had no problems with larvae at the sides, bottom or top when I did it this way, although they did seem to congregate a little bit in the upper central portion of the tank for the first couple days.

Matt

 

[EMBRYOGUY]

a L is alot more than i wanted to add. since temps are not matched when i add it in. i wanted to minimize vol. added. thanks matt for info. im only using 4 gallons to start with.

 

[mwp]

1L per day is standard "greenwater" technique for gobies...my phyto is at 68F (room temp) whereas the tank is running at 82-83F...didn't cause any problems and in fact has NEVER caused problems (other than excessive rotifer growth which can simply be sieved out). I actually have to reconsider what I said earlier, since I started out with 3 gallons and by a few days had 4 or 5 (might have added some new clean water along the way).

PS - I should mention we're talking LIVE phytoplankton cultures, not store-bought concentrates and such...

Matt

 

[EMBRYOGUY]

yes, ive been culturing live phyto ever since my first batch.

 

[EMBRYOGUY]

what happens is that when i add the green water, for the first 6 hrs they are fine swimming in the center, eating. as the green water gets absorbed, they than move back to the wall. so its like a yoyo affect!

 

[mwp]

It's wierd that they move to the wall, but perhaps that's to help with spotting prey...overhead lighting from what I've read (but haven't really experienced in my batches) can drive the vertical "location" of the larvae, but horizontally, I'd think that's directly related to the phyto density (as your comments suggest)..i.e. they start having difficulty simply spotting prey in the water column, so they move to the walls where they can see prey against the black walls (assuming you've blacked out the sides of the tank). My most recent effort (Batch VI) went into a tank completely shrouded by garbage bags

Matt

 

[EMBRYOGUY]

yeah ive painted my walls with matt black spray paint. i left one side open with a black removeable acrylic cover to view. but the funny thing is that i rarely put this cover on and the larvae are never on the front glass! LOl where there is no black paint.

im leaning towards the reflection maybe, since they always migrate to the left wall, away from the heather/bubbler. and no the bubbles are min. since i have larvae swimming near it without problems.

 

[mwp]

<a href=showthread.php?s=&postid=8841947#post8841947 target=_blank>Originally posted</a> by embryoguy
yeah ive painted my walls with matt black spray paint.

My spray paint (matt black) is terrific stuff! And only $49 a canister if you PM me now

i left one side open with a black removeable acrylic cover to view. but the funny thing is that i rarely put this cover on and the larvae are never on the front glass! LOl where there is no black paint.

It makes perfect sense. Phyto in the water clears out, and now the only thing that helps the babies find food is the black backgrounds. They don't congregate at the transparent tank side (which wouldn't be helpful to them in their quest for food).

im leaning towards the reflection maybe, since they always migrate to the left wall, away from the heather/bubbler. and no the bubbles are min. since i have larvae swimming near it without problems.

As my batch VI grew up they showed a preference for stronger currents.

I really think more phyto may solve the "wall hugging" and may help with the day 2-3 losses too.

Matt

 

[EMBRYOGUY]

yes matt, mine also show a pref. for stronger currents at the top

matt black lol for that price, could you come over and paint the tanks for me? lol

i would rather them swim in the water column. whats your plan to this? lol

 

[EMBRYOGUY]

matt your mailbox is full...

 

[mwp]

Fixed

More phyto is the plan my man...I really think that's gonna fix your woes.

Matt

 

[Baalz]

You can lay some screens under your light to dim it more if you think its to bright. But don't let the clowns freak you if they are hanging on the sides alot. Its when they are on the bottom that it can be bad not the sides. Mine hang out on the sides alot and more so as they get older. You just need to be thinking about not having them on the bottom for the first two weeks before morph. I feed the rots for like the first 5 days with a little phyto added. Keeps em off the bottom but they still will hang out on sides some. Then when they are on bbs I dont worry about the phyto addition anymore.

 

[EMBRYOGUY]

thank you baalz, i think im being paranoid. they never hang on the bottom and its not like most hand on the sides. i just thought they all should.

 

[mwp]

Once mine are going through meta they're all at the sides, but for those first few days, your critical period where you're having the losses, my percs are in the water column with the phyto.

Baalz comments regarding the bottom (where the larvae are literally banging their heads to get away from the light)...true. I think the fact that your larvae are going to the sides AND having big dieoffs, and your correlation between phyto feedings and it clearing out, I think the dieoffs are food related. Fixing the side-oriented behavior is not my actual concern..I think it's symptomatic of a food issue.

MORE PHYTO!!!



Matt

 

[EMBRYOGUY]

yeah you have a good point, my losses are coming on days 2 -4.

i just thought they have some reserve in there yolksac to sustain them for a a little bit.

matt, after you use your 1 L , how long does it take for that bottle to get "green" again? it seems when i start out with a small amt of green water in the 2 L bottle. it doesnt get green. it stays clear. the only time ive been able to maintain green water in the bottles is whenthey start out relatively green. i have a ton of light on them so im not sure why. air flow seems to be good. a good amt of bubbles every sec.

 

[EMBRYOGUY]

matt,

on my second batch, i added alot of phyto the night of the hatch , along with alot of rotifers. added some more the following morning. went away for rest of the day and came back late day 2 to find sign. loss. around 200. no water changes. nothing.

the morning of the hatch, with the sign green water, they alll looked great, swimming in water column. when i came back late day 2. water was clear and they were on the sides again.

so even though the phyto cleared up. they still had atleast a full day of good green water. is it possible day 2 they could not eat and die off that much?

 

[mwp]

I typically harvest about 50% of a bottle (so 1L out of a 2L culture). They typically get harvested every 7 days or so...thus why I think you'll need at least 7 cultures going (to harvest from 1 per day).

FWIW,

Matt

 

[mwp]

According to Wilkerson, dieoffs on the 2nd day are going to most likely be food related or transfer losses, but I think that transfer losses will typically show up the morning following (i.e. when I used the turkey baster vs. larval snagger).

Matt

 

[Baalz]

Load up on them rotifers.
I raise rotifers in 4 - 5 gal containers.. I dip as much as I can without stirring up debris. I do this out of all 4 and then rinse them before adding to babies. Once in the early morning and once in the evening has worked for me.